Note 4 - Earnings Per Share - Distributed and Undistributed Earnings (Details) - $ / shares	3 Months Ended		6 Months Ended
	Jul. 01, 2018	Jul. 02, 2017	Jul. 01, 2018	Jul. 02, 2017
Distributed Earnings (in dollars per share)	$ 0.07	$ 0.06	$ 0.13	$ 0.12
Undistributed Earnings (in dollars per share)	0.28	0.27	0.47	0.34
Total (in dollars per share)	0.35	0.33	0.60	0.46
Distributed Earnings (in dollars per share)	0.07	0.06	0.13	0.12
Undistributed Earnings (in dollars per share)	0.28	0.27	0.47	0.34
Total (in dollars per share)	0.35	0.33	0.60	0.46
Basic earnings per share (in dollars per share)	0.35	0.33	0.60	0.46
Diluted earnings per share (in dollars per share)	$ 0.35	$ 0.33	$ 0.60	$ 0.46